....I'm thinking about drilling some ventilation as I'm concerned about heat build-up shortening the life of the emitters.
So are those going into ceiling boxes? If so really get a good feel for the light coverage. For a 36" tank and 30degree lens I would suggest 3 lamps. The reason I went with a track light is I get the ability to use lateral movement in placement since Im using two pendants. I agree with ventilating the fixtures.
At one point I thought about the classic 50's pool hall light fixture with 3 glass green shades. That just wouldn't look right in our living room, so I went with the IKEA shades.